The tonal system came up in my mind because of how the time units seem to work so well for old school D&D and possibly 5e, but I'd have to look at it more. Bear with me, I'll get to how this thought exercise helps me.
A hexadecimal second is 1.31 seconds long. This would really change anything.
A hexadecimal minute is about 21 seconds. This could be considered a round. It's twice as long as I'd normally have a round, but I could say that you can take four actions in a round instead of my normal two actions in a round.
A hexadecimal maxime (there is no analogue in our current time system) is about 5 and half minutes long. I could call this a turn.
I am a pianist, so I can easily think in terms of two 16th notes makes an eighth note, four of them make a quarter note and so on.
Get on with the game part of this
In the game, two rounds make 1/4 turn. four rounds make 1/2 a turn. For spells that last for turns, I feel like I can track them easier. I have a circle for each spell that lasts turns and mark the time elapsed in quarters.
I do clothespin initiative, but I get two different colors of wooden clothespins and make two color clothespins. After determining the initiative order and placing them on my referee screen, after each person finishes their turn, I turn the clothespin around. When I see all the same color clothespins on my side, it's another round.
If I have yellow and green clothespins and start with the green side facing me, every time all the clothespins facing me are all green, that would mark a 1/4 of a turn. In the circle representing the spell, I quickly shade in 1/4 of the circle.
My old system was that since 10 rounds equals 1 turn, I would use tick marks for every two rounds.
Something to think about more.